I currently have a 645DF+ with IQ250 and was looking to update the firmware on the IQ250. However, I am getting conflicting advice different dealers.

Dealer One tells me that I should update my IQ to the latest firmware. In doing this I will get all of the benefits of the IQ3 series except the battery stuff. I will be using this with a 645DF+, not upgrading to XF yet...